An invading force, 10,000 strong, marches through a storm toward a fortress built into the side of a mountain. From a distance, the combatants look like ants -- menacing and alarmingly well organized. They rattle their spears and snarl through teeth that have never known modern dentistry, and when lightning strikes, it reveals their sheer numbers. Volleys of arrows fly, swords find their way to the weak spots around breast plates. Bodies on both sides hit the ground. This bloody affair is the Battle of Helm's Deep, from The Lord of the Rings: The Two Towers.

Script supervisors, editors, CG artists and actors all had better look out: "It's all over by 2045 -- we are no longer running the show." Following Paul Walker's death in 2013, the Furious 7filmmakers faced the delicate task of finishing the film using a digitally created version of the actor. To do so, they resorted to performance capture with the help of the actor's brothers, Caleb and Cody, as well as painstaking computer animation from a team at VFX house Weta. That was state-of-the-art in 2014. But imagine if, instead, a computer could have stepped in, watched all of Walker's performances in the previous Furious films, learning the minute details of how he walked, talked and even raised an eyebrow. And then imagine that artificial intelligence took over and itself helped to create a digital performance for Walker's character.

Following Paul Walker's death in 2013, the Furious 7 filmmakers faced the delicate task of finishing the film using a digitally created version of the actor. To do so, they resorted to performance capture with the help of the actor's brothers, Caleb and Cody, as well as painstaking computer animation from a team at VFX house Weta. That was state-of-the-art in 2014. But imagine if, instead, a computer could have stepped in, watched all of Walker's performances in the previous Furious films, learning the minute details of how he walked, talked and even raised an eyebrow. And then imagine that artificial intelligence took over and itself helped to create a digital performance for Walker's character. Now that the use of computer graphics is commonplace in movies and TV, artificial intelligence may be the most important technology to emerge in Hollywood.